Potential of renewable agricultural wastes in the smart and sustainable steelmaking process

The iron and steel industries are major players in economic development, however, pose a challenge to the environment due to the huge emission of greenhouse gases. Further, the depletion of fossil fuels makes a way for renewable energy sources. In this direction, biomass sources including agricultural wastes appear to be one of the alternatives to address the above challenges of fossil fuel scarcity and greenhouse gases. The lignocellulose biomasses are rich in carbon contents (39-57%). The agricultural wastes are being converted to biochar, bio-oil and syngas through thermochemical conversion to enhance heating values and fuel properties and applied to different plants in the iron and steel industries. The present review systematically focuses on smart technologies based on renewable energy concepts and waste heat recovery. The potential and scope of renewable biomasses to be utilized in the iron and steel making industries are deliberated. The characteristics of biomasses and their thermochemical conversion into value-added fuels are described. The concepts of waste heat recovery from the different sections of steelmaking processes for this conversion are outlined. The thermochemical conversion of biomass occurs at a temperature below 1000 degrees C while the steelmaking takes place above 1200 degrees C, which indicates the feasibility of efficient waste heat recovery. The recent developments toward the partial or complete substitution of fossil fuels with biomass-based renewable fuels in different steelmaking processes are discussed. Charcoal is a suitable replacement in the oxygen route of steel making, while biomass, charcoal and syngas are potential alternatives in the electric route. The implications of renewable sources as fuels towards emissions of greenhouse gases are emphasized. The replacement of fossil fuels with renewable biomass reduces CO2 emissions by 20-80%. The effective utilization of agricultural wastes also positively contributes to the local economy.

Automated summary

The iron and steel industries play a major role in economic development but also pose a challenge to the environment. The use of biomass as an alternative to fossil fuels shows promise and can help address the issue of greenhouse gas emissions. This review explores smart technologies based on renewable energy concepts and waste heat recovery in the iron and steel industries, discussing the potential and scope of utilizing renewable biomasses, as well as the thermochemical conversion of biomasses into value-added fuels.